The present invention relates to a styrene/macromonomer random copolymer. More specifically, the present invention relates to a styrene/macromonomer random copolymer that has excellent melt flowability as well as good heat resistance, chemical resistance, dimensional stability, elongation, flexural strength, impact strength, compatibility, and electrical properties. The present invention includes a method of preparing the styrene copolymer. Also, the present invention relates to a styrene/styrene derivative/macromonomer random terpolymer and a method of preparing the terpolymer.
In general, a styrene resin is prepared by radical polymerization. Since a styrene resin prepared by radical polymerization has an atactic structure as a whole, it has poor heat resistance and chemical resistance. A styrene resin with stereoregularity is prepared in the form of an isotactic structure or a syndiotactic structure. The former is polymerized by using a Ziegler catalyst and the latter is polymerized by using a uniform catalyst consisting of a titanium compound such as halogen titanium, alkoxy titanium, etc. with an alkylaluminoxane.
The styrene resin having a syndiotactic structure has good heat resistance and chemical resistance, but, on the other hand, it has poor impact strength. In order to overcome these shortcomings, methods of mixing a rubber, an inorganic filler, etc. have been attempted, such methods have limited usage. Further, since the melting point of the styrene resin is about 270xc2x0 C. and the degradation temperature is 310xc2x0 C., it is not easy to carry out such a process.
Recently, macromonomers with polymerization activity at the end of the chain have been developed and applied to various uses. The present inventors have developed a styrene/macromonomer random copolymer that has excellent melt flowability as well as good heat resistance, chemical resistance, dimensional stability, elongation, flexural strength, impact strength, compatibility, and electrical properties, which are required for engineering plastics. Further, the present inventors have developed a styrene/styrene derivative/macromonomer random terpolymer having excellent melt flowability as well as impact strength and other physical properties.
A feature of the present invention is the provision of a styrene random copolymer having excellent melt flowability, which is prepared by copolymerization of a styrene derivative monomer and a macromonomer and which is useful for engineering plastics having good heat resistance.
Another feature of the present invention is the provision of a styrene random copolymer prepared by copolymerization of a styrene derivative monomer and a macromonomer, which has good heat resistance, chemical resistance, dimensional stability, elongation, flexural strength, impact strength, compatibility, and electrical properties.
A further feature of the present invention is the provision of a method of preparing the styrene random copolymer prepared by copolymerization of a styrene derivative monomer and a macromonomer.
A further feature of the present invention is the provision of a styrene random terpolymer having excellent melt flowability, which is prepared by polymerization of a styrene monomer, a styrene derivative, and a macromonomer and which is useful for engineering plastics having good heat resistance.
A further feature of the present invention is the provision of a styrene random terpolymer prepared by polymerization of a styrene monomer, a styrene derivative, and a macromonomer, which has good heat resistance, chemical resistance, dimensional stability, elongation, flexural strength, impact strength, compatibility, and electrical properties.
A further feature of the present invention is the provision of a method of preparing the styrene random terpolymer by polymerization of a styrene monomer, a styrene derivative, and a macromonomer.
The above and the other features and advantages of this invention will be apparent from the ensuing disclosure and appended claims.
The styrene random copolymer according to the present invention is produced by copolymerization of a styrene monomer and a macromonomer, thus having at least two repeating units, the styrene derivative with a syndiotactic structure and the macromonomer. The macromonomer has polymerization activity via an ethylenically unsaturated group, such as a vinyl group, at the end of the chain. The repeating units of styrene derivative, and more particularly at least 50% syndiotacticity. The amount of macromonomer is about 0.1% to about 50% (0.1xcx9c50%) by weight based on the weight of the random copolymer. The melting point of the copolymer is 150xcx9c272xc2x0 C., and the weight average molecular weight is in the range of about 50,000 to about 2,000,000 when it is measured by gel permeation chromatography.
Thus, according to one aspect of the present invention, a styrene random copolymer is provided that includes at least one unit of styrene derivative and at least one unit of macromonomer, the at least one unit of styrene derivative being polymerized from a styrene derivative monomer of formula (1), the at least one unit of macromonomer being polymerized from a macromonomer of formula (2).
In the forgoing formulae, 
R1 is selected from the group consisting of hydrogen, halogen, and alkyl groups with 1xcx9c20 carbon atoms, R2 is at least one selected from the group consisting of saturated hydrocarbons with 1xcx9c20 carbon atoms, aromatic groups, and cycloalkyl groups with the proviso that R2 is not xe2x80x94COxe2x80x94 or xe2x80x94CH2xe2x80x94C6H4xe2x80x94, R3 is a saturated hydrocarbon group with 1xcx9c10 carbon atoms, X is at least one ion polymerizable monomer unit selected from the group consisting of monomers of formulae 
R4, R5, R6, R7, R8, and R9 are the same or different and are selected from the group consisting of hydrogen, halogen, alkyl groups with 1xcx9c20 carbon atoms, and alkoxy groups with 1xcx9c20 carbon atoms, R10, R11, R12, R13, R16, and R17 are the same or different and are selected from the group consisting of alkyl groups with 1xcx9c20 carbon atoms, R14 and R15 are the same or different and are selected from the group consisting of hydrogen and alkyl groups with 1xcx9c20 carbon atoms, R18 is selected from the group consisting of hydrogen and alkyl groups with 1xcx9c4 carbon atoms, R19 is selected from the group consisting of alkyl groups with 1xcx9c4 carbon atoms, and l is the degree of polymerization for X and is an integer from about 10 to about 1,000.
The amount of the macromonomer is 0.1xcx9c50% by weight based on the weight of the random copolymer, and the weight average molecular weight of the random copolymer ranges from about 50,000 to about 2,000,000.
According to another aspect of the present invention, the styrene random copolymer is prepared by polymerization of a styrene derivative monomer and a macromonomer in the presence of a catalyst comprising a transition metal compound, more particularly a Group IV transition metal compound, and an alkylaluminoxane.
Further, the present invention includes a styrene random terpolymer that is copolymerized from a styrene monomer, a styrene derivative, and a macromonomer, thus having at least three repeating units, the two styrenes with a syndiotactic structure and the macromonomer. The macromonomer has a polymerization activity viaan ethylenically unsaturated group, such as a vinyl group, at the end of the chain. The repeating units of the styrene, and more particularly have at least 50% syndiotacticity. The amount of macromonomer is about 0.1 to about 50% by weight based on the weight of the random terpolymer. The melting point of the terpolymer is 150xcx9c272xc2x0 C., and the weight average molecular weight is in the range of about 50,000 to about 5,000,000 when it is measured by gel permeation chromatography.
Thus, in accordance with an additional aspect of the present invention, there is provided a styrene random terpolymer comprising units of styrene monomer, units of styrene derivative, and units of macromonomer, the units of styrene monomer being polymerized from a styrene monomer of formula (1s), the units of styrene derivative being polymerized from a styrene derivative monomer of formula (1), the units of macromonomer being polymerized from a macromonomer of formula (2), 
said terpolymer being represented by formula (III): 
In the foregoing formulae, R1 is selected from the group consisting of hydrogen, halogen, and alkyl groups with 1xcx9c20 carbon atoms, R2 is at least one selected from the group consisting of saturated hydrocarbons with 1xcx9c20 carbon atoms, aromatic groups, and cycloalkyl groups with the proviso that R2 is not xe2x80x94COxe2x80x94 or CH2xe2x80x94C6H4xe2x80x94, R3 is selected from the group consisting of saturated hydrocarbons with 1xcx9c10 carbon atoms, m is a degree of polymerization for the styrene monomer and is an integer of about 400 to about 20,000, n is a degree of polymerization for the styrene derivative monomer and is an integer of about 5 to about 200, o is a degree of polymerization for the macromonomer and is an integer of about 1 to about 20, l is the degree of polymerization for X and is an integer of about 10 to about 3,000, and X is at least one ion polymerizable monomer unit selected from the group consisting of monomers of formulae (A) to (K): 
R4, R5, R6, R7, R8, and R9 are the same or different and are selected from the group consisting of hydrogen, halogen, alkyl groups with 1xcx9c20 carbon atoms, and alkoxy groups with 1xcx9c20 carbon atoms, R10, R11, R12, R13, R16, and R17 are the same or different and are selected from the group consisting of alkyl groups with 1xcx9c20 carbon atoms, R14 and R15 are the same or different and chosen from hydrogen and alkyl groups with 1xcx9c20 carbon atoms, R18 is selected from the group consisting of hydrogen and alkyl groups with 1xcx9c4 carbon atoms, and R19 is selected from the group consisting of alkyl groups with 1xcx9c4 carbon atoms.
The amount of the macromonomer is 0.1xcx9c50% by weight based on the weight of the random terpolymer, and the weight average molecular weight of the random terpolymer ranges from about 50,000 to about 5,000,000.
According to a further aspect of the present invention, the styrene random terpolymer is prepared in the presence of a catalyst comprising a transition metal compound, more particularly a Group IV transition metal compound, and an alkylaluminoxane.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.